How can food affect symptoms of irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) symptoms can occur regardless of what you're eating. However, if certain foods precipitate symptoms, these need to be avoided. Patients can develop sensitivities to specific foods. It is a good idea to first rule out lactose intolerance, gluten sensitivity (celiac disease) and infection, which can result in an alteration in intestinal function, abdominal bloating and cramping. Sometimes we try to shift our focus away from IBS as purely related to diet.
Laura Motosko, MSEd, RD
Nutrition & Dietetics

Irritable bowel syndrome (IBS) is a disorder of a sensitive digestive tract with symptoms of bloating, gas, constipation, diarrhea, or a change in function of the bowel. Stress and hormones are thought to have a role in causing IBS, unrelated to the type of food consumed. Sensitivity to foods is individual. High fat foods taking longer to digest can tend to aggravate symptoms in some people. A journal of food intake and symptoms is recommended to track foods that may increase IBS symptoms.

The recommended medical nutrition therapy prescribed by me for IBS also is helpful for healthy weight maintenance. I recommend small frequent, moderate fat meals of whole grains, fruits, vegetables, lean meats, beans, nuts, dairy or soy foods.

Lori Maggioni
Nutrition & Dietetics

Nutrition therapy for Irritable Bowel Syndrome (IBS) can help you feel less constipated and bloated. It can also help ease constipation and diarrhea. It is important to make changes to your diet gradually. Keeping a food diary or journal can help you track your intake and identify foods that cause your system to get worse.

Recommended foods include low fat or skim dairy, all ready-to-eat or cooked grains that your body tolerates, lean meat, eggs, poultry, or fish prepared without added fats. Soy food like tofu is another way to get adequate protein. You may eat any fruits and vegetables that your body is able to tolerate while avoiding the ones that may cause gas (see below). Limit fat to 1 tsp. of butter/margarine/oil or 1 Tbsp. of salad dressing per meal. When it comes to beverages, stick to non-carbonated and non-caffeinated beverages. Examples include water, decaffeinated coffee, and caffeine-free herbal tea.

Foods not recommended include full fat dairy products (such as whole milk, heavy cream, and cheeses made with whole milk), poultry with skin, meats that are marbled with fat, luncheon meats (including bologna, hot dogs, bacon, and sausage), fried foods and dried beans and peas if they cause gas. The following vegetables may cause gas: broccoli, cauliflower, brussel sprouts, cabbage corn, leeks, and onions. You also want to avoid prune juice and grape juice, as well as caffeinate coffee/tea and carbonated beverages. It is also recommended to avoid high-fat desserts such as pies, cakes, pastries, and doughnuts.

The best way to manage your IBS is to eat meals on a regular schedule. Aim for 5 to 6 small meals and snacks a day and try not to skip meals. A low-fat diet is often better tolerated. You may feel better if you avoid fried foods and foods prepared with added fats. It is also important to stay well hydrated – Aim to consume 6 to 8 cups of water per day.

For some people, irritable bowel syndrome flare-ups are triggered by certain foods. Carbonated drinks and foods that are hard to digest - like cabbage and beans - may cause excessive gas and bloating. Diarrhea or constipation may be caused by alcohol, chocolate, or milk. Some may have a problem with fatty foods, which may contribute to their stomachs emptying too quickly or too slowly. Other people with irritable bowel syndrome may be sensitive to citrus fruits, coffee, tea, or wheat. Discovering what your food triggers are and avoiding them can go a long way toward relieving your irritable bowel syndrome symptoms.

Specific foods may trigger IBS symptoms causing more gas and abdominal cramping or even diarrhea. There is no evidence that IBS patients have food allergies or that exclusion diets are effective but there may be symptom response to some exclusion diets.

Some IBS patients may test positive for celiac disease and should be recommended a gluten free diet. Fiber may cause increased gas/ bloat symptoms in some patients. Lactose intolerant patients should avoid dairy products or use lactaid milk.
Christine Marquette
Nutrition & Dietetics

Over 60% of your immune system is in your digestive tract. In addition, there are 4 different pathways that your immune system uses to fight off invaders. Type 3 and type 4 pathways can be triggered by food sensitivities, and these reactions can cause symptoms of IBS. The symptoms caused by these pathways can be delayed up to several days, which makes determining them simply by food journaling a challenge. 

Christie Korth
Nutrition & Dietetics

In my experience, as well as clients who I have worked with, food can effect the digestive tract by causing inflammation.  Such inflammatory responses are provoked by 2 immune system reactions called Immunoglubulin E (IgE) or Immunoglobulin G (IgG).  IgE reactions are immediate and produce histamine, which classifies this reaction as a true allergy (ie you break out in hives when you eat a strawberry).  IgG reactions are delayed hypersentivity responses  which cause the body to produce cytokines which cause inflammation.  The inflammation can occur in the gut, brain, and/or the respiratory tract.  Recent research on IgG is interesting when it comes to IBS and should be reviewed.

The top IgG reactive foods are generally diary, eggs, wheat, soy and nuts.  If you consume these foods, it could be worth it to give up the foods you may suspect are contributory to your symptoms for 30 days- 90 days.  Then reintroduce one food at a time to see if you have any reactions like stomach upset, cramping, constipation, loose stools, rashes, migraines, etc.  Any such negative reaction would indicate you should continue to stay away from said food. 

Jessica Crandall
Nutrition & Dietetics

Certain foods can be triggers to IBS. Speak to a RD about how to implement an elimination diet to determine which foods are triggers for you. They may be certain textures, spices, acidity, high fat, lactose, gluten, etc.

Judy Caplan
Nutrition & Dietetics
Foods can play an enormous role in IBS. Often times processed fiberless foods can cause constipation. It is important to eat foods that contain fiber such as whole grains, fresh produce, and beans. Start slowly so you don't experience lots of gas. Probiotics can also be helpful as can a diet low in certain sugars called oliogosaccharides.
Nell Stephenson
Nutrition & Dietetics

Many foods that comprise a large part of the typical diet today are sourced from grains, legumes, dairy and contain white sugar, all of which can wreak havoc on the GI tract.

Unfortunately, many of the recommendations commonly offered by specialists can make symptoms worse. All of the foods listed above have an inflammatory response in the body and lead to a condition called leaky gut and as such, should be elminated in order to allow the body time to heal.

The Paleo diet is an anti inflammatory diet which can help heal leaky gut.   A thirty day trial is a good way to do an experiment.   As symptoms begin to subside, digestion gets back to normal and the body begins to heal, one can see for themselves how foliowing this natural approach to eating really makes sense!

Certain foods contain substances such as caffeine, lactose or fructose, which can precipitate symptoms of IBS. Once these triggers are identified, people may have improvement of symptoms by avoiding them. Also, the addition of fiber to the diet can improve symptoms.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.